The function $f(x)$ defined by
$f(x)
= \begin{cases}
ax+b & \text{x ≥ 1 } \\
x^{2}+3x+3& \text{x ≤ 1}
\end{cases}$
is differentiable
- For a unique value of a and infinitely many values of $b$
- For a unique value of $b$ and infinitely many values of $a$
- For infinitely many values of $a$ and $b$
- None of the above